Methods of making amorphous alloy magnetic materials by liquid cooling or sputtering are well known. The method of liquid cooling provides the magnetic material only in the form of a ribbon or wire. The ribbon or wire can not be used as a magnetic thin film on a substrate unless it is bonded to the substrate by the use of an adhesive agent. This has the problem that the bonding strength between the film and the substrate is not always reliable due to secular deterioration of the adhesive agent. The method of sputtering has another problem in that it is very costly.
The conventional method of plating provides no other than a monolayer magnetic thin film. The monolayer thin film is formable on the substrate without the adhesive agent, even if the substrate is complicated in shape. However, the monolayer thin film tends to have scattered, uneven portions and is unable to provide a desired saturation magnetic flux density of more than 8000 (gauss).
The inventors of the present application have developed a method of alloy electroplating into the present invention, considering that the aforementioned problems might be solved by electroplating an improved magnetic multilayer thin film directly onto the substrate.
An object of the present invention is to provide a method of making a magnetic material in the form of a multilayer thin film by alloy electroplating. Another object of the present invention is to provide a method of making such a multilayer thin film that is superior in uniformity as well as magnetic characteristics and directly formable on the substrate, even if the substrate is complicated in shape.